My understanding is that under GPLv2, if you violate the terms of the license, your right to use the software under the terms of the license are instantly revoked, and there is no mechanism provided by the license for getting it back. In practice you have to go back to the copyright holder and ask permission.

Section 8 of GPLv3 does allow you to automatically get out of jail free if you fix the violation voluntarily or within a reasonable time period after an infringement notice. GPLv3 is much kinder to well-intentioned, inadvertent infringers.

In Cisco's case anyway, I think we can assume they've been knowingly violating for a lot longer than is reasonable.

Outside of drupal.org, the guys at Lullabot have some awesome resources (articles, videos, podcast).

I tried Mambo on a few sites a few years ago, one of which got hacked by a phisher within a few months (to be fair I hadn't been keeping up with security updates), so I quickly migrated them over to Drupal, which I had started using once the limitations of Mambo became apparent. I had a look at Joomla! soon after it forked from Mambo. It was supposed to have been substantially rewritten, but I couldn't see any significant differences.

My most immediate frustration with Mambo was that there was a lot of hard-coded markup that you couldn't cleanly override without hacking the core system. This may have changed in the last couple of years. Drupal's theming system, even at the time, was an order of magnitude more elegant; not necessarily easier, but much more flexible.

In fact Drupal v Joomla! is not a fair or useful comparison. If you just want a CMS that works out of the box, I'd guess you'd probably find Joomla! a happier experience. If you're a developer or a graphic designer who knows their HTML/CSS/PHP, or if you want to do something beyond the standard features of a CMS, Drupal is for you. It's said that Drupal is an application development framework that just happens to come with a CMS built-in. I was showing Drupal to someone earlier this year and he said, "Hey, this is like Rails!" Moreover much of the recent development in the Drupal ecosystem has been directed towards making it possible to build quite sophisticated database-backed applications without having to do any coding. Someone else once said to me "Hey, this is like Microsoft Access!" (I was a little less happy with this comparison.)

To return to the subject of the parent post, if you are a one-or-two-person web development shop, and you want to do as much as possible while having to support the smallest amount of code, you can't go past Drupal. For any particular problem it may not be the best solution, but it's a satisfactory solution for a vastly wider range of problems than any other system I'm aware of.

Oh, and all free software, all the time. You never know when you'll come up with some re-usable code, or want to use a sizable chunk of some other GPL-licensed code, so make it clear that the client has the product to use as they wish under the terms of the GPL (or whatever), but they don't have the copyright. Anything else is a legal nightmare, and I've never encountered any resistance to this. Anybody not knowledgeable enough to be comfortable with the GPL probably doesn't care about the legal details anyway. Anybody who has dreams of striking it rich with their own proprietary web application is going to be a problem client you should avoid.

• Don't try to do everything yourself. Subcontract to other developers with complementary strengths who play nice with others: a couple of graphic designers, maybe a copywriter, sysadmin, or sales/accounts/office admin genius.
• Don't try to support too many products/platforms. If you use a different tool for every project, just keeping up with security updates will either become a full time job, or else you will get hacked at some point (I did). Life got a lot easier for me when I decided to specialise in Drupal.
• Get yourself a VPS or two. Don't bother with shared hosting - it's too expensive and limited. Your clients' hosting fees should pay for the effort _you_ put into keeping their sites ticking over, not for your hosting provider's cPanel licenses.
• About 20% of your time will be spent on technical work. The rest will be negotiating and hand-holding. You've got to develop some social skills.
• Insist on using a professional graphic designer (unless you're a graphic design genius yourself). No matter how adamantly a client initially insists that the look of their site isn't important, they will change their mind.
• Pick your clients carefully. Don't be afraid to say no. Unless you're a scam artist, say no to anybody who proudly proclaims their computer illiteracy. If they don't understand what you do, they won't appreciate it. Likewise avoid clients who think they need a website, but don't know why. Ask them what they want to achieve with the project.
• You probably won't find small/medium clients who will be happy with paying per hour. Demand a 50% deposit at commencement of work, plus timely delivery of whatever you need from them to complete the job.
• Don't take on anything that you think will take more than a fortnight's work, for which you should quote four to six weeks. Every project takes longer than you would expect, so if you expect something will take a couple of months, you may be out of business before you get paid. Split large projects into smaller stages if necessary. Even the best clients (not to mention developers) will have a tendency towards feature creep. Make it clear that additional ideas, no matter how brilliant, are for later stages of development. Throw around some buzzwords like "agile" and "iterative".
• Don't expect to do more than four billable hours a day. Don't let yourself burn out, and keep it interesting. If you don't do a lot of reading and stretch yourself with the occasional hobby/charity project with features that paying clients won't generally ask for, you'll be a miserable dinosaur in three years.
• Mind you, don't do discounts/freebies unless you really believe in the cause. If you wouldn't do a fun run, sell raffle tickets, or shave your head for them, don't do a website for them. Be clear about the limits of what you'll do.
• Did I mention you should develop with Drupal? Check out this awesome presentation on catering to small clients with Drupal.
• Catch up on the Rissington podcast. They're more graphic design focused, but have lots of useful tips for dealing with clients and organising your business, amusingly delivered, and advice about cheese.